A model of road effect using line integrals and a test of the performance of two new road indices using the distribution of small mammals in an Atlantic Forest landscape

► We combine GIS and Differential Calculus of Several Variables to introduce two new road effect indices, IRE and AVIRE. ► We evaluate their performance compared to other models to explain small mammal abundance. ► AVIRE obtained the best performance of forest specialist species. ► The nearest road distance obtained the best performance to generalist species. ► AVIRE allows for separating the effect of roads to the effect of habitat.